Fog generator



Sept. 2, 1947. RQSELUNb 2,426,846

FOG GENERATOR I Filed Feb. 10, 1944 4 Sheets-Sheet 1 HEATING .UNIT

INVENTOR. :Hqro /a A. Pose/ana AL/TORNEY p -2,1947 HAROSEL'UND 2 426,8 6 7 FOG GENERATOR Filed Feb. 10, 1944 4 Sheets-Sheet 2 INVENTOk. Hare/ d 14. Rose/um bb Pww ATTORNEY Sept. 2, 1947. H. A. r-eos|:| u u: v 2,426,845

FOG GENERATOR v Filed Feb. 10, 1944 4 Sheets-Sh'et .5

INVENTOR. Harold A. Rose/and A TTORNE Y se 't. 2, 1947.

Filed Feb. 10, 1944 INVENTOR. Hare/d 14. Rose/ ad ATTORNEY 4 Sheets-Sheet 4 I Patented Sept. '2, 1947 Harold A. Roseluntl,

The De Vilbiss Com poration of Ohio Toledo, Ohio, assignor to pany, Toledo, Ohio, a cor- Application February 10, 1944, Serial No. 522,193

1 Claim.

a high temperature. Upon discharge into the atmosphere the vapor thus formed condenses into a persistent cloud of minute oil particles.

the heat created.

Other objects and advantages of the invention will be apparent upon reading the following description with reference to the drawings.

-he principal components of the generator assembly include supply tanks for fog oil, gasoline and water;

Among the features contributing to the various objects and advantages of the invention are the to the set of heating coils; of a singl magneto for supplying the ignition spark to both the gas engine furnishing the operating power for the unit and the gasoline burner in the heating unit; an eificient gasoline burner adapted to this particular, apparatus; a coil arrangement in the heating unit for efiiciently transferring the heat In the drawings:

Fig. 1 is a side elevation of a fog generator embodying the invention;

Fig. 2 is a combination side elevation and, vertical' section with parts broken away of the heating, unit;

Fig. 3 is a vertical section of the gasoline burner;

Fig. 4 is a top view water connections; and

Fig. 5 is an elevation of the discharge nozzles and nozzle manifold.

Referring more in detail to the drawings, particularly to Fig. 1, the apparatus as shown has a supporting base I on which is mounted a gasoline engine 2 and the heating unit 3. The gasoline engine 2' through its pulley 4 and belt 5 drives blower 6 and the fog oil pump 1'. The pulley on the oil. pump is indicated at 8 while the pulley on the blower is not shown.

The pump draws oil from supply drum 9 through insert pipe of the fog oil pump and manifold Htfrom charge nozzles i9. From. the latter the vapor is discharged into the atmosphere where it is immediately condensed or precipitated into fog form. Gauge shows the temperature of the oil vapor within the manifold is;

During its progress through the coil M; the oil is progressively heated and finally volatilized from; the combustion heat produced by gasoline burner 2| This burner is furnished gasoline through supply piping 22'. Gasoline is drawn from the storage tank 23 through tubing 24' by the pump 25 which is mounted on the side of the base of the engine 2 and is'driven' by an arm through the engine wall which is motivated by a cam on the main crank of the engine, details of which are notshown. Q

Just above the pump 25 there is a T connectionj26', fastenedlto' tubing 24' to which a branch tubing 21 is connected for supplying gasoline to the carburetor. 28 of the engine. Air reaches the carburetor through air cleaner 29. Gravity flow from the tank 23 is sufficient to bring the gasoline to the carburetor.

The blower 6 drives air tangentially into annular space 30 surrounding the heating chamber. This air, after spiraling through space 30, passes upwardly to chamber 3| at the top of the heating unit and hence into the gasoline burner 2|. This air furnishes oxygen for the burning of the gasoline. It passes down through the burner into the cylindrical combustion chamber 32, outwardly from the bottom end of chamber 32 with the gas residue of combustion, hence up between the sections of the coil l4 and out opening 33 into the atmosphere.

.The air in traveling the heating chamber, cools the outer concentric walls of heating unit 3 and thus reduces the possibility of an operator being burned on contacting the outside surfaces; the preheating that is thus given the air contributes to efiicient combustion and the conservation of thermal energy.

It has been determined that a certain amount of water flowing through with the fog oil improves the operation of the apparatus. The water and resultant steam minimize the formation of coke within the heater coils and also by their dampening effect, acts to prevent flaming or spontaneous combustion of the oil vapor as it is discharged into the atmosphere. Approximately one part of water to fourteen parts or oil has been found to be sufiicient. A water tank 34 is provided from which water passes through tubing 35 and 36 (see Fig. 4) into the inlet chamber of pump 1. Between tubing 35 and 36 is interposed a metering port member 31 with port cleaning needle 38 which is used occasionally to insure that the port does not become clogged. The needle is normally held away from theport by spring 39 and has an exterior button 48 by which it may be manually depressed.

There is a by-pass within the oil (and water) pump from its outlet to its inlet side which is controlled exteriorly through hand wheel valve 4|. By manipulation'of this valve the amount of oil and water passing to the heating unit may becontrolled as its adjustment permits more or less oil and water to circulate through the bypass.

The. gauge 58, mounted on the side of heating unit 3, is connected'through the wall of the unit with the coil within. It shows the pressure of the 'oil passing through the coil and thereby indicates the flow rate as set by valve 4|.

The water is mixed thoroughly into the oil through the agitation the two materials receive when passing through the pump. This dispersement of the water causes it to be more effective in preventing coke deposits and flaming at the nozzle than would be the case were it merely injected as a stream into the oil line by another pump or through the use of a Venturi injector.

From the magneto of the engine, which is mounted in a well known manner in association with'the main shaft of the engine, extends cable 42 to the spark plug 43 of the engine. Another cable 44 also extends from the magneto. This enters housing 4511. where it is clipped to the top of electrode 45 mounted in burner 2| for furnishing an igniting spark.

The gasoline reaching the burner through piping 22.enters annular chamber 46. From the chamber 4 6 a spaced series of nine downwardly extending ports 41 communicate with a second annular chamber 48. While in this chamber the through space 30 around gasoline, after the unit is once started, is volatilized by heat passing through the walls of the burner from the combustion chamber below; and the gas vapor thus formed passes upwardly into extension 49 of chamber 48 and out of inwardly directed annular slot 50. Here the gasoline vapors are intermixed with the air entering the burner from chamber 3| above it, and this air after passing downwardly through large center opening 5| past the slot 50 continues into the reduced center 52 as well as into the series of passages 53 encircling the opening 52. The passages 53 are separated by spiral vanes or partitions 54 which give the air and gasoline vapor a whirling motion. The mixture of air and gasoline vapor ignites upon entering the combustion chamber 32.

When the generator is first put into operation there is no heat tovolatilize the gasoline entering chamber 48 and a certain amount of it will pass downwardly in liquid form through bleeder passages 55 which are located in four or live of the vanes 54 and terminate above trough 56. The gasoline thus collected in trough 56 is ignited by sparks from the end 51 of the electrode 45 and the heat from this burning gasoline passing through the heater wall starts the volatilization of the gasoline in annular chamber 48. The resultant gas vapors are themselves ignited after passing through slot 50 and when combined with air they reach the region of flames arising from the trough 56. The gasoline initially arriving in trough 56 is quickly consumed and no more reaches it as the gasoline subsequently entering chamber 48 is vaporized before it has a chance of passing down through passages 55.

The amount of heat developed within the combustion chamber is well beyond that ordinarily obtained in a chamber of comparable size.

In securing this result the use of gasoline as a fuel is an important factor. Gasoline burns more rapidly than fuel oil and for this reason its rapid combustion in a chamber of fixed size may release considerably more heat than would be possible with another fuel.

The large volume of air delivered through the burner into the chamber is another contributing factor. It supplies the large quantity of oxygen required and carries the heat into contact with the coils. Then the flow of oil and water through the coils is at a high rate and this rapidly conveys away the heat created.

Because of the necessity for lightness in order to have the generator as portable as possible and because of the rough handling the unit is given during transportation, ordinary refractory materials for the walls of the combustion chamber are unsuitable. The use of a stainless steel shell takes care of these conditions. This withstands the high temperature needed to bring the oil and waterto around 900 F. As other materials fail in one way or another for the purpose, stainless steel is also used for the tubing in the coils. Both for the combustion chamber and the coils a light gauge of this steel is entirely satisfactory because of its relatively high creep strength and resistance to corrosion at elevated temperatures. The use of such a gauge metal keeps the size and weight of these units down to a minimum.

For operating purposes the. generator would ordinarily be set upon the ground at the site where the fog is to be created, but, however, may be operated upon the truck by which it is transported.- Supplies of .-fog o'l, gasoline, and water to replenish that previously placed in the tanks of 4| and allowing 5 the apparatus may be brought along in extra drums.

When the supply tanksare all filled and it is desired to put the generator into operation the gasoline engine is first started. All valves are left in closed position until it is determined that the engine is operating satisfactorily and has reached its proper speed. The valve in the gasoline line 22 from th pump 25 to the burner is then opened. As soon as the gasoline becomes ignited and combustion is in progress Water but not oil, is permitted to pass through the pump 1, and piping l3 into the coils. This flow of water keeps certain portions of the coils from overheating and the heat of the resultant steam passing out the nozzles 19 is recorded on gauge 20. It may thus be determined when the heating unit has reached its operatin temperature. At this point the oil valve I2 is opened by swinging handle I 2a and portion of water. to the coils there will be insulficient heat to vawasted by being discharged into the atmosphere in the form of unvaporized drops. This condition may be corrected by opening by-pass valve some of the oil to recirculate through the pump. Consequently less oil will travel to the coils.

When it is desired to stop the generation of the fog, the 011 valve protects the coils from bein overheated through absorption of the heat remaining in the combustion chamber.

The water supply is then shut off and the gasoline engine stopped. The driving connection between the engine and the blower and pumps results in the operation of the latter when and if the engine runs and their stopping when the engine is stopped.

Having thus described my invention, What I claim is new and desire to secure by United States Letters Patent is:

In a fog generator, a vaporizing chamber for HAROLD A. ROSELUND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

